The field of digital imaging has been growing rapidly over recent years. Many individuals have large collections of digital images including hundreds, if not thousands, of digital images. Various digital imaging applications and systems have been developed enabling users to view their digital images on soft-copy displays. The digital images can also be used to make prints for displaying in photo albums or in picture frames, or can be used to make various imaging products such as photo calendars, photo books, coffee mugs and the like.
In many applications, it is desirable to form composite images that can be used to simultaneously view a plurality of digital images. For example, such composite images can be used as a page of a photo book or can be used to make a photo calendar.
FIG. 1 shows an example of a composite image 100 created using three digital images 102, 104 and 106. The composite image 100 also includes a background 108. Digital imaging applications that can be used to form composite images 100 often provide the user with an ability to specify the content to be used for the background 108. Typically, the content for the background 108 can be selected from a menu of predefined backgrounds patterns. The predefined background patterns can include solid backgrounds having a variety of colors, or can include patterned backgrounds.
Users often find it difficult to find a background that they like from the set of predefined backgrounds. For example, the colors of the predefined backgrounds may not be compatible with the colors of the images that they wish to include in the composite image. Additionally, they may not want to repeatedly use the same backgrounds (e.g., for different pages in a photo book). As a result, there is a need for a method to provide custom backgrounds that can be used for a composite image.
U.S. Pat. No. 7,000,192 to Allen, entitled “Method of producing a matted image usable in a scrapbook,” describes a method of producing a matted image usable in a scrapbook. The method comprises the steps of displaying a digital image having a matte area surrounding an image opening. A plurality of color selections from which a user can select a preferred color are provided and the selected color is used in the matte. The color selections can be obtained from an analysis of the digital image, thereby ensuring that the matte color matches a color from the digital image. However, simply selecting colors that occur frequently in an image can provide unacceptable results. For example, some colors may not be easily distinguishable to a viewer if they are part of a texture. Additionally, some colors may be found in image locations that do not complement a matte, or may correspond to colors that are unacceptable for a matte. While a user may choose a suitable color that overcomes these deficiencies, it is desirable to automate the color selection process to enable users to be efficient and effective.
It is known in the art to create color palettes by analyzing the colors in an image. Such color palettes can be used for purposes such as displaying digital images on color displays capable of representing only a limited number of colors (e.g., 256). For example, the article “A new approach to palette selection for color images” by Balasubramanian et al. (Journal Imaging Technology, Vol. 17, pp. 284-290, 1991) discloses a method for determining a palette of colors based on the distribution of colors in the input digital image. A similar method is disclosed in U.S. Pat. No. 6,859,210 to Luo et al., entitled “Method for representing a digital color image using a set of palette colors based on detected important colors.” Such methods are also known to be useful for determining website color palettes.
U.S. Pat. No. 6,711,291 describes the use of colors found in an image to provide a textual caption with a selected color within the image. The selected color can be found within the image by forming a color histogram of the entire image. Colors within the histogram are then candidate colors. A candidate color having suitable contrast with the area in which the textual caption is to be placed is selected and the textual caption of the suitably-contrasting color combined with the image. However, this process can still yield undesirable results. A color found in the histogram at a high frequency may be, for example, part of a large textured area that includes multiple colors. Thus, the high-frequency color used in, for example, a matte, may not provide a pleasing combination, since the specific color within the textured area may not be readily apparent to a viewer.
There is a need therefore, for an improved method for providing a background to be used for forming a composite image, wherein the background is customized to be compatible with the images to be displayed in the composite image.